Howdy Matt45,
I'm not sure which cartridge you are referring to, .45 Colt or .45 Schofield. I don't believe the reproduction Henry rifles are chambered for the .45 Schofield. I think you would have feed problems with a Henry rifle chambered for .45 Colt if you load it with .45 Scholfield rounds as they are too short.
As to loads being safe in both guns, any safe load listed for a Colt SAA in a loading manual will be safe.
The Henry Rifle will be stronger than the Schofield pistol.
Silver Rings